22k gold 22k gold: China's national standard GB11887—2008 "Provisions and Naming Methods for Metal Purity of Jewelry Fees" refers to K gold with gold content ≥9 1.6%. However, it is as low as 9 1.3% abroad. 22k gold was once used as the standard gold for gold coins. Some rings on the market also use 22k gold. However, its texture is still soft and cannot be used for setting gems.
Thousands of gold with a gold content of not less than 999 is called thousands of gold, which is the highest value in the naming of jewelry color. The stamp is thousands of gold, 999 gold, gold999 or g999. The imprint of gold jewelry includes the manufacturer's code, material and purity, such as: X Gold 990, XAu990, X Pure Gold, etc.
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Thousands of pure gold has the characteristics of good ductility and low hardness. Pure gold is soft to fold, and copper bars are laborious to fold. Or use a pin (nails are also ok) to draw it. If the force is not big and the traces are obvious, it will be gold and pure gold, while copper will exert a little more force and the traces are slightly worse. Folding soft and hard is only suitable for rings, gold wires and the like, but it is more difficult for gold bars, gold coins and gold bricks.
Pure gold is soft and has low hardness, which can draw shallow marks with nails and leave teeth marks with teeth biting. golden island, gold ornaments with high fineness are softer than those with low fineness, and the more copper they contain, the harder they are. The bending method can also test the hardness. Pure gold is soft and easy to bend, and the lower the purity, the more difficult it is to bend.
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